1. Field of the Invention
This invention relates to a data processing system including a performance measurement system and more specifically to a data processing system capable of measuring performance using a timer provided therein.
2. Description of the Prior Art
Performance measurement of a data processing system which executes instructions in main storage by fetching the instructions can provide an important guideline for development of a more advanced system in the next development phase, for example and for design of software.
FIG. 1 is an example of an existing system. An existing performance measurement of a data processing system is performed, for example, by the logic circuit hardware as shown in FIG. 1. A processing system 1 is provided, for example, with the counter circuits 4-1 to 4-n for each performance measurement item such as an instruction appearance frequency etc. and a selection circuit 3 selects a point for performance measurement through the control of control circuit 2 and thereby each counter circuit 4-1 to 4-n is operated by trigger signals determined for respective measuring items. According to such a prior art system, a large amount of hardware provided only for performance measurement is necessary, the performance measurement items are fixed and performance measurement for other items than those stored in the computer system cannot be measured. However, if performance measurement is carried out by software operating under a normal operating system, such a program for performance measurement realized by the software can be designed not to have any adverse effect on the result of a performance measurement.